P980: THE ROLE OF PLATELET AND ENDOTHELIAL MICROPARTICLES AND DOPPLER ULTRASOUND SCREENING IN THE ASSESSMENT OF THROMBOTIC READINESS IN MULTIPLE MYELOMA AND NON HODGKIN LYMPHOMA, PROSPECTIVE STUDY
Authors: Magdalena Olszewska-Szopa, Urszula Zaleska-Dorobisz, Agnieszka Zubkiewicz-Kucharska, Iwona Prajs, Tomasz Wróbel, Lidia Usnarska-Zubkiewicz
Journal: HemaSphere (2023)

Topic: 14. Myeloma and other monoclonal gammopathies - Clinical Background: Microparticles (MPs), spherically formed fragments of the cell membrane, play potentially important role in the thrombotic processes. Currently used scales assessing the risk of thrombosis in lymphoproliferative neoplasms seem imperfect. Aims: The goal of this study was to determine the value of platelet microparticle (PMP) and endothelial microparticle (EMP) levels assessed before therapy. The obtained results were confronted with the image of the veins of the lower limbs evaluated in the Doppler ultrasound examination before and after therapy. Methods: Data from 76 patients diagnosed with multiple myeloma (MM) and non-Hodgkin’s lymphoma (NHL) treated in the period of January 2015 to May 2020 in Wroclaw Medical University were prospectively analyzed. The control group consisted of 12 healthy volunteers. Platelet MPs were identified by CD61, endothelial MPs by CD133, tissue factor was identified by CD142 antigen. Doppler ultrasound (US) of lower limbs was performed before and after therapy. Statistical analysis was conducted using the program Statistica (TIBCO Software Inc. 2017, version 13). Results: Patient characteristic is presented in Table 1 - Monoclonal protein type:IgG/IgA/LCD/non secretory 27/8/4/3 ISS stage:I/II/III 10/20/15 Renal function:normal/impared 38/7 Histological type:DLBCL/MCL/FL/ALCL 14/10/4/3 Ann Arbor:I/II/III/IVB+/B- 2/6/7/1628/3 ISS: International scoring system; DLBCL: Diffuse large B cell lymphoma, MCL: Mantle cell lymphoma; FL: Follicular Lymphoma; ALCL – anaplastic large T cell lymphoma Thrombosis characteristics is presented in Table 2 - Baseline:MM vs NHL 16/45 6/31 Symptomatic vs Asymptomatic 1/22 21/22 After therapy:MM vs NHL 16/38 5/23 Age, sex, clinical stage (ISS for MM and Ann Arbor for NHL) did not affect thrombosis presence in US in a statistically significant manner. There was a higher rate of US thrombosis, although not statistically significant, in patients with MM vs NHL, both before and after treatment: 35,5 vs 19% and 42 vs 22% respectively. Higher percentage of thrombosis was observed in kappa than lambda MM, Table3 - Light chain type thrombosis No(%) no thrombosis No(%) kappa 11 (68,75%) 2 (12,50%) p=0,0356OR 4,888995% CI 1,1130-21,4737 lambda 3 (18,75%) 16 (55,17%) non secretory 2 (12,50%) 1 (3,45%) Higher levels of PMPs and EMPs were found in MM/NHL compared to control group, observation was statistically significant. There were no statistically significant differences between baseline MP levels in MM and NHL patients. CD133 MP level was lower in lambda MM than in kappa MM (p=0,028). Microparticle correlations in MM/NHL patients were statistically significantly more strongly expressed than in control group. No differences were observed in the levels of microparticles in patients with or without thrombosis in US. Summary/Conclusion: There was a large discrepancy between the occurrence of symptomatic vein thrombosis and the thrombosis diagnosed by US in patients with newly diagnosed MM and NHL. Asymptomatic thrombosis was more common in patients with MM compared to NHL. Thrombosis risk was higher in kappa light chain compared to lambda light chain MM. The percentages CD61+MP and CD131+MP did not differ between patients with MM and NHL, and did not differ depending on the presence of US thrombotic changes. Percentages of CD61+MP and CD131+MP with CD142+ co-expression were higher in the study group compared to healthy controls, and correlated to tissue factor, which may be the laboratory evidence of thrombotic readiness Keywords: Lymphoma, Myeloma, Thrombosis